A self-model can meet every condition for change and still not change: its distortion cleared, its old organization destabilized, an accurate account of its own trouble in hand, and the reorganization still failing to take. What decides whether it holds is not the force applied or the truth of the insight, but the structure waiting to receive the change — and not every structure can hold one. This is not a fact about minds. A scientific paradigm yields to accumulated anomaly only when a successor stands ready to receive the field; a self-model yields to accumulated distortion only when a more coherent structure is ready to receive it. The two are one structure under two descriptions, and so the question of what makes a receiver sufficient is structural, not psychological. We propose five criteria a sufficient receiver must meet, and define the structural efficiency of any configuration as the degree to which it meets them. Efficiency, so defined, fixes the condition under which a structure can be displaced and the law by which one structure then displaces another. Three falsifiable predictions follow. This is a theoretical proposal requiring prospective validation, not a clinical instrument.